Oeka Kids tablet

This page is a stub. The best information we have on the Oeka Kids tablet is currently in the forum. As such, this information may be incorrect, but it seems to be a working implementation.

Input ($4016 write)

7  bit  0
---- ----
xxxx xxAS
       ||
       |+- Strobe (0 = Latch, 1 = Read back)
       +-- Advance to next bit

To advance to the next bit, set A to 0 and then to 1. Bits can only be read while S is set to 1.

Output ($4017 read)

7  bit  0
---- ----
xxxx xDSx
      ||
      |+-- 0 if strobe is 1, 1 otherwise.
      +--- (Inverted) Serial data if strobe is 1, 0 if strobe is 0.

The serial data is returned most significant bit first, and inverted.

$4017.2
   ^
   |  <-- <-- <-- <--
   XXXXXXXXYYYYYYYYBA
   ||||||||||||||||||
   |||||||||||||||||+- Click
   ||||||||||||||||+-- Stylus is touching tablet
   ||||||||++++++++--- Stylus Y, scaled to 0-255
   ++++++++----------- Stylus X, scaled to 0-239